Percussion fuse



` PERCUSSION FUSE Filed July so 1921 Patented July 17, 1923.

UNIT-ED STATES PATENT OFFICE,

RUDOLF HAAS, OF BADEN, GERMANY, ASSIGNOR TO TECHNO SERVICE CORPORATION,

OF NEW YORK, N. Y A CORPORATION OF NEW YORK.

PERCUSSION FUSE.

Serial No. 488,607.

(GRANTED UNDER THE lPROVISIONS OE THE ACT OF MARCH 3, 1921, 41 STAT. Il., 1313.)

T o all whom t may concern.'

Be it known that I, RUDOLF I-IAAs, a citizen of Germany, residing in the city of Baden-Baden, State of Baden, Germany, have invented certain new and useful Improvements in Percussion Fuses (for which I have filed an application for German patent, tiled August 2, 1918), of which the following is a specification.

This invention relates to percussion fuses for projectiles, bombs and the like, which operate on impact and cause the charge to explode. It relates more particularly to i percussion fuses which operate when the projectile strikes the object of suitable resistance at any angle, and it is for the purpose of causing,` action with equal sensitivej ness whether the projectile strikes head on,

sidewise or at any intermediate angle. In particular, it is adapted for use in bombs or shells which are to be dropped from aeroplanes and from low altitudes before the shell or bomb assumes an axial direction of movement or any other pre-arranged direction of motion. This condition would be involved in dropping bombs from low altitudes, from aeroplanes, in attacks on infantry, as well as heavy night bombing operations.

Fuses of' previous design which have aimed to assure operation in other than axial impact of' the bomb or shell, have not been sufhciently sensitive or their action has been variable, depending upon the varying conditions of use, and it is to provide an accurate, sensitive, and in every necessary characteristic more advantageous fuse, that involves the objects of this invention.

For purposes of illustration, the accompanying drawing); shows one form of embodiment of my invention, in which- The one ligure shows a cross-section on the axis of the fuse with the dotted outline of the adjacent portion of a bomb, shell or the like, to which it would be attached.

The body portion A of the fuse has the base plug B screwed into it with the central vent B while the threaded exterior. a serves to screw the fuse into the adjacent body portion D of the bomb or shell containing the charge which the fuse is intended to explode under the predetermined conditions.

The interior cavitv C formed in the body A is thus closed by the base plug B in order to confine and properly support the elements which cause the action necessary to effect the ignition at the predetermined time.

These elements contained in the cavity C comprise an annular ring of metal E of a suitable mass carefully predetermined because the relative momentum of this part in conjunction with other parts determines the proper action of the fuse. Within the ring E there are two plungers, the one F fitting into one end of the ring, the other G fitting in the other end of the ring, both being counterbored from their base and adapted to receive a spiral spring H in a position that tends to separate the plungers with a proper predetermined pressure to assure the cooperation of the different elements. The plunger F has the tiring pin J secured at its axis and of a size to'freely move through the coils of the spring H and of a length which provides for the point penetrating the primer by puncturing the disc L, when the predetermined conditions for firing are realized, so that the charge communicating the firing control through the aperture M ip due course reaches the main charge of the siell.

IVhile suitable safety pins may be used to prevent any accidental discharge of the fuse, such are known and are not the subject of my present invention, and the further description of parts and their operation may be assumed to be supplemented by other features of construction,to insure safety in handlingshells or bombs, or for other reasons.

In case of impact of the fuse in the direction of the arrow I which would correspond to an axial impact of a shell when this fuse is used las a nose fuse, the momentum of the plunger G would overcome the spring H, causing the firing pin J to effect the discharge. If, however, the impact is at right angles, as indicated. at the arrow II, then the momentum of the ring E with its momentum mass, tends to force a lateral movement of both plungers F and G and the form of 'the ends of these plungers and their supporting' cavities, are so arranged that with the predetermined ring mass, the lateral momentum permits sufiicient lateral movement but accompanied by the forcing together of the two plungers so that against the predetermined resistance of spring H, their mutual approach results in the firing pin penetrating the primer with the desired firing effect. This is accomplished lby having the'head of the plunger F formed with the conical face f so that the end rests in the cavity K which has the walls or a conical surface k of the desired angularity with respect to the axis so that the lateral strain due to the momentum check actuating ring E will permit a lateral movement of plunger F and an axial movement in the direction of plunger G. Likewise, the head of plunger G has a conical face g which engages a conical face Z) counterbored in base plug B, the inclination of which engaging faces is such as to permit the necessary lateral movement under the effect of the lateral check of the mass or ring E, and with it the axial movement of plunger G in the direction of plunger F, to cause the action of the firing pin on the priming charge. The mass of the plungers F and G is such that with a lateral impact their co-operation with the end confining cavities or recesses will tend to effect mutual approach with the confining ring as a guide to preserve their axial positions, but the additional element of mass in the ring E may be so proportioned that it will insure with certainty substantially uniform action on lateral impact in which it more than supplements the momentum of the plungers by being made substantial and is the main factor as a momentum mass for affecting the discharge upon lateral impact. Furthermore, this substantially added mass effective for lateral impact or any impact other than axial is .so fashioned that the ring may slide axially without in any way augmenting or aiecting the momentum of the plungers in t-he truly axial direction-nor does it affect or in any way impede their movement. ln other words, the construction is such that the axial and radial sensitiveness are independent of each other and the arrangement and permissible size and form of parts is such that the radial, or lateral, sensitiveness can be made equal to the axial sensitiveness. The arrangement furthermore avoids the chance of jamming or catching of the parts and with the .suitable selection of material the elements are readily preserved; as, for example, making the plungers of copper with a suitable material in ring and in the end recesses which will not cause corrosion of surfaces under ordinary conditions of storage and delayed use.

The inclination of the surfaces 7c and b may be varied, and their precise angle or curvature will be determined for 'the specific cases of use with due regard to the relative mass of all parts upon which the action is dependent due to momentum. Likewise, for reasons of manufacture or to meet the predetermined conditions of actuation, the complementary surfaces f and y] will be varied or determined to suit the specific case involved.

It will be seen, also, that ring E may be of a greater length, in fact, a close fit axially within the cavity C, and thereby be restricted or prevented from axial movement because its function is lateral, but this may not be to the detriment of a free lateral movement and the outer edges at the ends may be curved although its length may be close to the length of the cavity, thereby permitting what little canting may result from an oblique impact.

Thus it will be seen that the sensitiveness to detonation may be measured by determining the distance which it is necessary for a fuse to fall on ground of a certain hardness in order to cause ignition. The character of my invention having the known factors of momentum of parts and an angularity of engaging surfaces and their friction, the sensitiveness of my fuse may be readily predetermined and confirmed and established by experiment. lf, for example, a fuse is intended to function in every direction of impact on dropping` from a height of thirty ards onto loose sand, the lowest sensitiveness, i. e., for least favorable direction of impact, is accurately calculated. Then, if it has a very unequal sensitiveness for different angles of impact, for instance, in the ratio of one to ten, the same fuse would ignite in the most favorable direction on a drop of three yards. |This would be considered a very low factor of safety in handling and use, and the safety factor for transportation, loading into releasing apparatus on aeroplanes, and emergency landings would be very low. But. if the fuse had a greater uniformity of action, as in the ratio of one to two, a height of fifteen yards. in a similar case, would be necessary for ignition in the most favorable direction of iinpact. This would mean a safety factor five times as great, as compared with the very unequal sensitiveness of the case previously considered. Accordingly, the greatest pos sible uniformity in sensitiveness can be appreciated and it will be seen that the foregoing detailed description of my fuse sets forth fully how the elements determining sensitiveness can be properly proportioned so that the ratio of uniformity of action at different angles of impact is improved far beyond the practice heretofore current in this art.

Between the direct radial or lateral impact and the axial impact, all the different angles and in fact every degree of direction of impact would have a firing response that would differ in proportion to the combined components of 4'pressure and motion of the actuating parts, relative to their effect in the direct radial or direct axial direction. Thus, the momentum mass involved-in the ring E is proportioned with respect to the mass in each of the plungers and the Obliquity or angle resisting their lateral movement at their end supports, as well as the strength ofthe spring tending to seat them in the recesses at either end. The combined components in any one direction may not be made in any one design to be exactly equal, but my construction serves to so design a fuse for any given conditions that the variation at any angle of impact will vary but slightly.

The end surfaces of the plungers and the faces with which they are engaged are, of course, some of the factors in establishing the uniformity of action, and these are determined and may be given any inclination or curvature to effect the desired results. These end contacts with the mass of each of the parts and the strength of the spring are jointly designed to give the desired results. As in the example illustrated, the proportion of parts is such as to give very uniform action in all directions, with a gradual variation reaching a maximum at about 45 from the axis.

Fuses so constructed may be placed in the end of a projectile or bomb or at the base, sides or elsewhere as in usual practice, and more than one may be present on the same projectile but only for the purpose of minimizing the chances of defects. It will be seen that one fuse is all that is necessary to meet the conditions of impact at different angles, thereby providing in a single fuse what might in other cases be accomplished only by employing a number of fuses each only operative in substantially one direction.

The body ofthe fuse may be variously constructed, the essential parts for the desired action being set forth in their relative importance in the above description, and the method of attachment to the main bomb or projectile body may be varied, and likewise the material and the dimensions and details of construction may be modified in many ways without departing from my invention, but what I claim and desire to secure by Letters Patent is:

l. A percussion fuse comprising a plunger, a firing pin carried by said plunger, a second plunger, a. ring-shaped weight surrounding said plungers, said plungers being free to move axially inside saidy ring.

2. In a percussion fuse, two plungers having conical ends, a cavity containing said plungers, recesses at the ends of said cavity which co-act with the ends of said plungers, a firing pin carried by one of said plungers, and a momentum mass surrounding said plungers.

. 3. In a percussion fuse, two plungers having inclined ends, a ring-shaped mass surrounding said plungers, a cavity containing said plungers and said mass, recesses at the ends of said cavity which co-act with the ends of said plungers, and a. firing pin carried by one of said plungers.

fi. In a percussion fuse, two plungers movable both axially and radially, a ringshaped weight surrounding said plungers, said weight co-acting with said plungers to cause them to move axially toward each other when said weight moves radially, and means whereby said weight is non-effective upon an axial movement.

5. A percussion fuse comprising aplunger, a firing pin carried by said plunger, a second plunger, a ring-shaped weight surrounding said plungers, and means for causing said weight to assist the axial Inovement of said plungers when said fuse strikes laterally, and be non-effective when the fuse strikes axially.

6. In a percussion fuse, a ring-shaped mass, two plungers inside said mass, inclined surfaces on which said plungers can slide, in such a manner that a radial movement of said mass will cause an axial movement of said plungers, and be non-effective on the position of said plungers with an axial movement.

7. In a percussion fuse, 'a ring-shaped mass, two plungers inside said mass, curved surfaces on which said plungers can slide, in such a manner that a radial movement of said mass will cause an axial movement of said plungers, and be non-effective on the position of said plungers with an axial movement.

8. In a percussion fuse, two plungers capable of both axial and radial movement, inclined surfaces on which said plungers can move, and a mass surrounding said plungers which can move radially, but having noneffective axial movement.

9. In a percussion fuse, two plungers capable of both axial and radial movement, curved surfaces on which said plungers can move, and a mass surrounding said plungers which can move radially, but having noneffective axial movement.

l0. A percussion fuse comprising a plurality of plungers and means of support permitting axial movement due to momentum, a co-acting mass and inter-engaging means with said plungers whereby lateral momentum of said mass will cause axial movement of the plungers, and a firing pin and primer operatively associated with said' plungers.

11. A percussion fuse comprising two plungers, inclined surfaces on which said plungers can move, and a mass associated with said plungers in such a way that its radial movement will cause the plungers to move axially, While its axial movement will have no efect upon the plungers.

12. A percussion .fuse comprising two plungers, curved surfaces on which said .plungers can move, and a mass associated with said plungers in such a Way that its raidal movement Will cause the plungers to .move axially, While its axial movement will have no effect upon the plungers.

14. A percussion fuse comprising two plungers, curved surfaces on which said plungers can move, and a mass associated with said plungers, said mass being` capable of radial movement, but incapable of axial movement.

In testimony whereof, I have signed my name to this application, in the presence of two subscribing Witnesses, this fourth day of July, 1921.

RUDOLF HAAS.

Witnesses FRANZ GIMINGEM MAX STBAUss. 

